14 CFR 29.175: Demonstration of static longitudinal stability.

(a) Climb. Static longitudinal stability must be shown in the climb condition at speeds from Vy − 10 kt to Vy + 10 kt with—

(1) Critical weight;

(2) Critical center of gravity;

(3) Maximum continuous power;

(4) The landing gear retracted; and

(5) The rotorcraft trimmed at Vy.

(b) Cruise. Static longitudinal stability must be shown in the cruise condition at speeds from 0.8 VNE−10 kt to 0.8 VNE + 10 kt or, if VH is less than 0.8 VNE, from VH − 10 kt to VH + 10 kt, with—

(1) Critical weight;

(2) Critical center of gravity;

(3) Power for level flight at 0.8 VNE or VH, whichever is less;

(4) The landing gear retracted; and

(5) The rotorcraft trimmed at 0.8 VNE or VH, whichever is less.

(c) VNE. Static longitudinal stability must be shown at speeds from VNE − 20 kt to VNE with—

(1) Critical weight;

(2) Critical center of gravity;

(3) Power required for level flight at VNE − 10 kt or maximum continuous power, whichever is less;

(4) The landing gear retracted; and

(5) The rotorcraft trimmed at VNE − 10 kt.

(d) Autorotation. Static longitudinal stability must be shown in autorotation at—

(1) Airspeeds from the minimum rate of descent airspeed − 10 kt to the minimum rate of descent airspeed + 10 kt, with—

(i) Critical weight;

(ii) Critical center of gravity;

(iii) The landing gear extended; and

(iv) The rotorcraft trimmed at the minimum rate of descent airspeed.

(2) Airspeeds from the best angle-of-glide airspeed − 10kt to the best angle-of-glide airspeed + 10kt, with—

(i) Critical weight;

(ii) Critical center of gravity;

(iii) The landing gear retracted; and

(iv) The rotorcraft trimmed at the best angle-of-glide airspeed.